I recommend "World Order" (2014) by Henry Kissinger, if you haven't read it yet. He goes into details and the historic background to the points you describe. Importantly, he compares the notion of the Western nation-state against other forms of world order, like the tribal systems in the Middle East, and the single king and empire of China.
Central to the European nation-state is the 1648 Peace of Westphalia, where more than hundred represented empires, states and cities sat down to put an end to decades of war. The outcome was the novel idea and mutual agreement that "I'll let you do what you like in your state - if you give me the same right in mine". This was against the backdrop of the Catholic church spreading their religion by the sword, backed by the Holy Roman Empire. Of course it did not put an end to wars, but at least it established a common framework by which peace could be built around.
Over the next centuries, there have been endless attempts at exporting this idea, and lately "bring democracy", and give people "freedom". However, without the historical background, the concept of a nation-state gets lost in translation. Some see it as blasphemy to their religion, others as a contradiction to their world view. In addition, especially in the 20th century, borders have been re-drawn completely arbitrarily, causing never-ending bickering.
Mix in of poverty; low value of life (lots of people, and a die rather than live forever mentality); plus the points you already mentioned. The situation in the Middle East is starting to look rather predictable. In fact, with a tin-foil hat on, the last US wars and military action in Iraq almost looks purposefully designed to continue the chaos and schisms. We've always been at war with Eurasia?